吸附杂多化合物对亚硝酸根的电催化还原

详细地研究了吸附在热解石墨电极表面的ＳｉＭｏ１２Ｏ４０４－以及Ｄｙ（ＳｉＭｏ１１Ｏ３９）２１３－和吸附在玻碳电极表面的Ｐ２Ｗ１８Ｏ６２６－的电化学行为，结果表明这些杂多化合物修饰电极在酸性条件下均对ＮＯ２－的还原有很好的催化作用，其催化电流与ＮＯ２－的浓度的平方根里线性关系。     

第四周期过渡金属磷钼三元杂多酸聚吡咯薄膜修饰电极及其电催化性…

合成了第四周期过渡金属磷钼三元杂多酸类化合物，采用电化学聚合法研制了该类杂多酸－聚吡咯薄膜修饰电极，该电极制备过程简便，快速，研究了膜电极的电化学行为，发明掺杂膜电极性能稳定，对酸性水溶液中的Ｈ２Ｏ２，ＮＯ２，ＣｌＯ３，ＢｒＯ＾－３，ＩＯ３等物质具有较好的电催化还原作用，初步探讨了电催化还原机理。     

杂多化合物催化性能的研究—第四周期过渡金属取代的钼磷三元杂多化合物在环己烯氧化反应中的催化作用

过渡金属单取代的杂多化合物［（ｎ－Ｃ４Ｈ９）４Ｎ］８－ｎ［ＰＺｎ＋ＢｒＭｏ１１Ｏ３９］（Ｚ＝Ｍ２＋ｎ、Ｆｅ３＋、Ｃｏ２＋、Ｎｉ２＋、Ｃｕ２＋）对以过氧化氢为氧化剂的环己烯氧化反应具有良好的催化性能．基于动力学、红外光谱及电化学方法的研究，对反应机理作了讨论．认为这类取代的杂多化合物与Ｈ２Ｏ２作用形成了活性中间体，活性中心为参与取代的过渡金属离子．     

杂多化合物催化性能的研究——第四周期过渡金属取代的钼磷三元杂多…

过渡金属单取代的杂多化合物（ｎ－Ｃ４Ｈ９）４Ｎ ８－ｎ对以过氧化氢为氧化剂的环己烯氧化反应具有良好的催化性能。基于动力学、红外光谱及电化学方法的研究，对反应机理作了讨论。认为这类取代的杂多化合物与Ｈ２Ｏ２作用形成了活性中间体，活性中心为参与取代的过渡金属离子。     

硅钼钨杂多阴离子-聚吡咯膜修饰电极的制备及其电化学性质研究

用电位扫描方法将混配型杂多阴离子α－ ＳｉＭｏ３ Ｗ９Ｏ４０４－ （ 简写为α－ ＳｉＭｏ３Ｗ９） 催化剂固定在导电聚吡咯膜电极上,从而制得具有表面功能的α－ ＳｉＭｏ３Ｗ９ 掺杂的聚吡咯膜修饰玻碳电极．该电极具有良好的电化学活性和稳定性,并对ＮＯ２－ 的还原起电催化作用．实验结果表明,α－ ＳｉＭｏ３Ｗ９ 在膜中的还原过程由溶液中的三步单电子还原转化为一步双电子和一步单电子还原．     

三缺位杂多化合物K8[P2W18Mo2CO2（H2O）2O68].MoO6.15H2O…

合成了杂多化合物Ｋ８［Ｐ２Ｗ１８Ｍｏ２Ｃｏ２（Ｈ２Ｏ）Ｏ６８］．ＭｏＯ６．１５Ｈ２Ｏ，依据ＸＲＤ、ＩＲ、ＵＶ－Ｖｉｓ及ＸＰＳ确定了其晶体结构的晶位原子价态，考察了该化合物催化Ｈ２Ｏ２分解动力学行为。     

混合价化合物的研究（Ⅱ）——电化学及现场光谱电化学方法研…

以电化学和现场紫外－可见－近红外及现场ＦＴＩＲ光谱电化学方法对Ｄａｗｓｏｎ结构杂多阴离子（ＨＡｓ２Ｍｏ１８Ｏ６２）＾５－在非质子介质（ＣＨ３ＣＮ）中的电还原过程进行了研究，结果表明，该杂多阴离了在非质子介质中经历４步单电子还原反应，所产生的杂多蓝阴离子在近红外区出现宽广的价间是荷转移吸收带，而红外区Ｍｏ＝Ｏ端键及Ｍｏ－Ｏ－Ｍｏ桥键的特征吸收峰在还原后均有不同程度的红移。     

三缺位杂多化合物K_8［P_2W_（18）Mo_2Co_2（H_2O）_2O_（68）］·MoO_6·15H_2O的合成、结构及催化H_2O_2分解研究

合成了杂多化合物Ｋ８［Ｐ２Ｗ（１８）Ｍｏ２Ｃｏ２（Ｈ_２Ｏ）２Ｏ（６８）］·ＭｏＯ６·１５Ｈ２Ｏ，依据ＸＲＤ、ＩＲ、ＵＶ－Ｖｉｓ及ＸＰＳ确定了其晶体结构和配位原子价态，考察了该化合物催化Ｈ２Ｏ２分解的动力学行为。     

Strandberg型杂多阴离子（Se2Mo5O212）^4的合成和晶体结构

利用还原－氧化重构法（简法ＲＯＲ法）合成了具有Ｓｔｒａｎｄｂｅｒｇ型含硒的杂多化合物Ｋ３Ｎａ．（Ｓｅ２Ｍｏ５Ｏ２１）．２Ｈ２Ｏ的单晶，结构测定表明，此化合物属单斜晶系，阴离子包含通过共边和共顶点相连的五聚ＭｏＯ６八面体，组成八面体的５个金属原子近似形成五角平架，２个ＳｅＯ３三角锥加在五角平面的上下方。     

Keggin结构合钒混配型杂多蓝的离析和性质研究

本文利用控制电位电解法首次制备出三元、四元含钒混配型－电子杂多蓝Ｋ４Ｈ２《ＳｉＶ＾ⅣＭｏ２Ｗ９Ｏ４０］．１２Ｈ２Ｏ和两电子杂多蓝Ｋ４Ｈ５［Ｓｉ＾ⅣＶ＾ⅤＷ９Ｏ４０］．１１Ｈ２Ｏ通过元素分析，ＩＲ、ＵＶ－可见电子光谱，ＥＳＲ、ＸＰＳ和Ｘ射线粉末衍射对产物进行了表征和性质研究，结果表明：杂多酸盐还原为杂多蓝后仍保持Ｋｅｇｇｉｎ结构，但结构发生畸变，畸变程度随钒原子数值多而增大，还原电子具有一定的离域性     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).